This research involves the study of the chemistry of 4- and 5-covalent organo-phosphorus intermediates. Mechanistic and synthetic investigations are being carried on. Both long- and short-range projects are underway with the ultimate goal the use of 4- and 5-convalent phosphorus chemistry in the synthesis of new anticancer agents. At present projects are underway concerned with: alpha and Beta-scission processes of R4P. intermediates; specific syntheses of products containing the bis-(2-chloroethyl)amino functionality; conformational investigations of cyclophosphamide analogs.